In the packaging of bulk materials, various proposals have been put forward and are currently in use. All of these are directed towards facilitating the packaging, storage, transport and/or subsequent discharge of large quantities of materials such as milk powder.
One bulk material package which enables the substantially rectangular shape of the package to be maintained when it is full of the material is that which is marketed under the GAMBO (trade mark). This is described and claimed in New Zealand Patent No. 233890 for example.
The present invention has particular application in its use with a GAMBO((trademark)) bag, but those skilled in the engineering and packaging arts will appreciate that the present invention can find application in improving the manufacture and design of other types of packaging and is not limited to large plastic bags of the GAMBO((trademark)) type specifically.
In large flexible bags such as the GAMBO((trademark)) bag, an insert within the outer film provides for the maintenance of the rectangular shape of the flexible bag when it is filled. However, the provision of such inserts within the outer film has proved difficult or at least time consuming and expensive.
Previous methods of welding these inserts have also allowed air to be entrapped between the insert and outer pack. This has made winding up of a continuous roll impractical.
The present invention, therefore, has as one object to provide a flexible bag having an insert/or a method of manufacturing same, which will overcome or at least alleviate problems in such bags and/or their manufacture, to the present time, or which at least will provide the public with a useful choice.
Further objects will become apparent from the following description.
According to one aspect of the present invention, there is thus provided flexible packaging of indefinite length providing a plurality of interconnected but separable flexible packages each having a respective insert positioned and secured within an outer flexible film, a transverse slit across a top layer of the outer flexible film defining the commencement of one of the bags providing at least part of the access into the interior of the outer film for the insertion of the insert.
Preferably said indefinite length of flexible packaging material may be gusseted to produce four plies of film, the packaging having substantially transverse incisions through at least three of the said plies leaving one of said plies intact to define the boundaries of a separable individual package having a leading edge and a trailing edge, an insert being provided for each individual package via the incisions and welded to the outer layer by welds running substantially parallel to the sides of the package, an area between the welds being left unsealed to allow air to escape from between the insert and the outer layer as the material, in use, is wound up.
Preferably, the packaging may have a further weld extending substantially parallel and adjacent to the leading edge of the outer layer, one or more further welds extending substantially parallel and adjacent to the trailing edge of the outer layer, and a plurality of further longitudinal welds joining the top gusset trailing edge of each package to the top gusset leading edge of the adjoining package.
Preferably the trailing edge of a leading package is connected to the leading edge of a following package by means of a flap created in one or more of the plies of said leading package proximate the trailing edge of said leading package and positioned or folded to extend between said trailing edge of said leading package and said leading edge of said following package.
According to a further aspect of the present invention, a flexible package is provided as a bag separated from the above defined continuous packaging.
According to a further aspect of the present invention, there is provided a method of forming continuous flexible packaging to provide a plurality of interconnected but separable flexible packages, said method including the transporting of an indefinite length of flexible outer film past a cutting means, moving the cutting means relative to the outer film in cutting only a top portion of the outer film and leaving a bottom portion intact, said method further including the insertion of an insert into the packaging at each slit so formed, providing sealing means to seal across at least part of the slit and in front of the slit to define a closure for an end of a preceding package and further providing securing means to secure said insert in position within the outer film.
According to a further aspect of the present invention, a method as above defined includes a continuous gusseted outer film, the cutting means cutting through three of four plies formed by the gusseting of the continuous film, the method further including the opening out of the film to enable the insertion of the insert and further providing for the re-gusseting of the outer film.
According to a further aspect of the present invention there is provided a method of forming a plurality of flexible packages, the method including:
providing an indefinite length of gusseted flexible packaging forming four plies.
forming transverse welds between the outer edges of the top ply and the outer edges of the second ply and transverse welds between the outer edges of the third ply and the outer edges of the lower ply, said welds extending partially but not entirely across the width of said gussets;
creating an incision adjacent and in front of the transverse welds through at least the top three of the four plies, leaving one ply intact, to define a trailing edge of an individual package in front and a leading edge of an individual package behind;
introducing an insert into the flexible packaging through the incision;
welding the insert to the flexible packaging in a plurality of locations such that in use the bag when filled with product deforms into a required shape, the welds running substantially parallel to the sides of the packages;
welding the insert to the flexible packaging at substantially the leading edge of the insert, the weld extending substantially between and transverse to the first welds;
welding the insert to the flexible packaging at substantially the trailing edge of the insert, the weld extending partially between and transverse to the first welds such that an area between the first welds is left open to allow air to escape from between the insert and the outer layer.
Preferably the welds of the paragraph immediately above may be formed separately.
According to a still further aspect of the present invention, a continuous flexible packaging and/or a flexible package provided as one of a plurality of such packages as part of a continuous flexible packaging of indefinite length and/or a method of manufacturing same are substantially as herein described.
Further aspects of the this invention, which should be considered in all its novel aspects, will become apparent from the following description given by way of example and possible embodiments thereof, and in which reference is made to the accompanying drawings.